Record Players Explained For The Streaming Generation

How do you consume your music, these days? Aside from on the radio, that is. Do you play MP3 or other files on your phone and computer, or perhaps do you stream from an online service? If you’re really at the cutting edge though you’ll do none of those things, because you’ll be playing it on vinyl.

The legendary Technics SL1200 direct-drive turntable, as used by countless DJs. Dydric [CC BY-SA 2.5)], via Wikimedia Commons.
The legendary Technics SL1200 direct-drive turntable, as used by countless DJs. Photo by Dydric CC-BY-SA 2.5
A few years ago reporting on a resurgence of sales of vinyl records was something you would never have expected to see, but consumer tastes are unpredictable. Our red-trousered and extravagantly bearded hipster friends have rediscovered the glories of the format, and as a result it’s popping up everywhere. For those of us who are old enough to have genuinely been into the format before it was cool again, the sight of Sergeant Pepper and Led Zeppelin II on 12″ at outrageous prices on a stand at the local supermarket is a source of amusement. It’s good to see your first love back in vogue again, but is it really the £20($25) per album kind of good?

With the turntable having disappeared as an integral part of the typical hi-fi setup the new vinyl enthusiast is faced with a poor choice of equipment. Often the best available without spending serious money at an audiophile store is a USB device with the cheapest possible manufacture, from which the playback will be mediocre at best. We’ve lost the body of collective knowledge about what makes a good turntable to almost thirty years of CDs and MP3s, so perhaps it’s time for a quick primer.

If you talk to a certain type of audiophile you will encounter a barrage of myth and pseudoscience on almost any topic relating to audio, and vinyl is no exception. It’s simplest for the purposes of this article to say that it is possible to play back a vinyl record such as to achieve a very high standard of audio reproduction given good quality equipment, and leave it at that. We’re not going to descend into audiophile fantasy, nor are we going to wax lyrical about turntables that will cost you more than your car. Instead we’re going to look at what makes a turntable, and hopefully help you pick one which will neither damage your records or sound bad.

How Vinyl Recordings Work

Close-up magnification of a 45RPM vinyl record, showing the audio waveform in each groove. The red lines are 1mm apart. Alex:D [Public domain], via Wikimedia Commons.
Close-up magnification of a 45RPM vinyl record, showing the audio waveform in each groove. The red lines are 1mm apart. Public domain photo by Alex:D.
There was a time when describing the operation of a record player would have been unnecessary as they were ubiquitous, but we want this to be a primer to serve all generations so it’s worth a quick diversion.

A record is a thin plastic disc into the surface of which is cut a spiral groove. Analogue audio is expressed as variations in the wall of the groove, and played back through a needle being placed in the groove and held stationary as the record is rotated anticlockwise on a turntable.

The vibrations of the needle are converted into electrical audio signals which are amplified for your hi-fi system. The discs hold recordings on both sides, and can be found in 12″, 10″, and 7″ variants. Long-playing albums typically require a rotation speed or 33⅓ RPM, while singles usually rotate at 45RPM. You’ll also see reference to earlier 78RPM records and rare 16RPM talking book records, but they are out of the scope of this article.

The groove itself would originally have carried mono audio, but later recordings were adapted for stereo by expressing the right and left channels in its opposing walls. An equalisation curve is applied to the audio before recording in the vinyl, this reduces the bass and thus the area taken up by the groove and the chance of the needle jumping out of it. A corresponding reverse curve must be applied in your playback device’s preamplifier, this is referred to as the RIAA curve after the industry organisation that specified it. The best visualization we’ve ever see for these grooves is with an electron microscope; and amazing trick performed by Ben Krasnow.

A youthful rite of passage for hackers of old was to play music from a record with a piece of paper inserted into the split end of a sharpened matchstick that formed the needle, this serves to demonstrate how accessible and simple this technology can be. Despite this simplicity though, to achieve good playback results you’ll need something a little better. We’ll now go through the individual components of your record player, describe their operation and varieties, and help you spot the good and the bad.

The Platter And Drive

A substantial aluminium platter on a belt drive turntable, with its mat removed.
A substantial aluminium platter on a belt drive turntable, with its mat removed.

It’s easy to describe the complete device you’ll play back your vinyl on as a turntable, without considering the turntable itself as an important component. We’ll now take a minute to look at it, and split it into its components: platter, bearing, and drive system.

The platter provides the circular flat surface upon which the record sits as it rotates. It will often have a rubber or similar mat on top of it to provide an acceptable surface to avoid damaging the record. The job of the platter is to rotate without vibration or flexing, so a good platter should be rigid, greater than the size of a 12″ record, and have a significant mass. You’ll see them most frequently as aluminium castings, though high-end turntables have been made of a wide variety of materials. By contrast cheap turntables almost always have lightweight plastic platters that provide no damping, and easily warp.

Jockey wheel drive on an ancient and rather grubby 1950s turntable.
Jockey wheel drive on an ancient and rather grubby 1950s turntable.

The bearing at the centre of the platter has the job of allowing rotation to continue without excess friction or vibration. There are platters that float on a layer of oil, spin on ball bearings, rest on a tapered spindle, and more. Cheap plastic platters will often have minimal attention to this important component, instead simply resting at the bottom of the spindle and relying on the friction between plastic and metal being low enough that the drive system can overcome it.

To rotate, the platter must have a drive system, and this is often touted as a marketing feature of the complete turntable. The drive does not have to be particularly powerful except in special applications such as DJ turntables, it simply has to be as smooth and vibration-free as possible and rotate the platter at the correct speed. Ancient turntables may have a jockey-wheel drive against a rim on the underside of the platter, but you’ll want to look for either a belt drive or a direct drive. Belt drives as their name suggest insulate the platter from vibrations through a rubber belt, while direct drives couple the platter directly to the shaft of a motor.

The belt-drive mechanism in close-up. The lever on the left changes speed by shifting the belt between different widths of the motor spindle.
The belt-drive mechanism in close-up. The lever on the left changes speed by shifting the belt between different widths of the motor spindle.

The choice of motor on a turntable is important, for through the motor comes most of the vibration that can affect playback. Look for twin-pole AC motors in a belt-drive turntable, and avoid shaded-pole motors. Very cheap plastic belt drive turntables often have small and vibration-happy DC motors.

Direct drive motors by comparison will often have the rotor magnets fixed in a ring on the underside of the platter, locating over a ring of stator electromagnets on the turntable chassis. They will be driven by a multiphase AC supply in a similar manner to a stepper motor, and the quality of both motor and drive will depend on the price of the unit. The legendary Technics SL1200 series turntables as used by countless DJs use this arrangement, though it’s arguable whether or not their high cost owes more to the legend than the reality.

The Tonearm

The tonearm takes the form of a balanced arm on a pivot that carries the cartridge and needle assembly over the record, and has to ensure that the correct forces are exerted on the record by the needle. Too much force either downwards or sideways will compromise playback quality and damage both record and needle.

The tonearm fulcrum, showing typical tracking weight and anti-skate adjustments.
The tonearm fulcrum, showing typical tracking weight and anti-skate adjustments.

A tonearm should have two accessible adjustments, tracking weight and anti-skate force. The tracking weight and anti-skate force settings should be defined by the manufacturer of your cartridge and needle, and will be specified in grammes. Cheap turntables will have these preset by the manufacturer or may miss them entirely, their presence is a good indication that the turntable is of some level of quality.

The tracking weight is simply the weight exerted by the needle on the record, and it will normally be in the region of a gramme or so. In most cases it is set by means of a counterweight on the other end of the tonearm that can be moved back and forth on a screw thread. There should be a dial on the counterweight calibrated in grammes. To set the tracking weight, first adjust the weight until the tonearm balances on the level, then adjust the weight back until the required tracking weight setting is shown on the dial.

The anti-skate force is a force applied to the tonearm that pulls it towards the edge of the record. This counteracts the force applied to the tonearm towards the centre of the record by the friction of the disc, with the desired result of reducing groove wear. There is usually a spring that is tightened or loosened by means of a small calibrated knob, simply turn to the value in grammes.

The tonearm itself can be found in a variety of different shapes, both straight and curved. It should be a metal tonearm, avoid turntables with plastic tonearms as a tonearm should be as rigid as possible. There are a lot of audiophile theories about the perfect shape for a tonearm, but the idea is to ensure that the cartridge axis is always at right angles to the groove and that the arc it tracks is as good an approximation to a straight line as possible. You’ll find hotly contested arguments over straight tonearms versus S-shaped ones, but you are probably better placed concerning yourself with your tonearm’s quality than its shape.

The Cartridge And Needle

An Ortofon moving-magnet cartridge in its removable headshell.
An Ortofon moving-magnet cartridge in its removable headshell.

The business end of a turntable is a tiny diamond needle that sits in the groove on the record, and transmits the vibrations up its mounting arm to a cartridge. The cartridge converts these vibrations into electrical impulses, which are sent down the wires to your RIAA preamp — the “Phono” input on your amplifier. On some turntables the cartridge sits in a removable headshell rather than being attached directly to the end of the tonearm.

You will see three types of cartridge, in ascending order of quality of price: ceramic, moving magnet, and moving coil. Ceramic cartridges use a piece of piezoelectric ceramic to generate the audio signal and are typically found on cheap turntables, while most reasonable quality cartridges will be moving magnet designs in which a tiny magnet vibrates within a coil of wire. High-end audiophiles will probably go for moving-coil designs in which the magnet stays stationary and the coil vibrates.

As long as the needle is not worn or damaged, and the tonearm adjustments have been made correctly, it should not matter in terms other than audio quality which type of cartridge you use. However you do not have to descend into audiophile silliness to find a decent moving-magnet cartridge to be a better choice than a ceramic one.

Mounting The Turntable

If you’ve made it this far you’ll have gained an understanding that vibration is the chief enemy of the turntable owner. We’ve talked about vibration from the drive system, but what about that from the environment?

There was a time when a cheap “Music centre” hi-fi would have a plastic turntable moulded into its top. It would be an integral part of the unit, and any vibrations in the surrounding environment from traffic or passers-by would find their way directly to the needle. Thus you had to tread carefully, or else the record would skip and jump.

Higher quality turntables will thus incorporate some form of spring and damper system, with the aim of removing these vibrations before they can affect playback. Typically this will mean a set of springs preloaded by the mass of the turntable, but you may find elaborate oil-filled damper systems as well. You will need to ensure that your turntable incorporates some kind of suspension.

So… What Should I Look For?

If you’ve read the advice above, you should now have some idea of what makes a decent turntable. You are looking for rigid components and as vibration free a design as possible, a rigid platter with some mass coupled to a belt or direct drive, with a good quality metal tonearm and a moving-magnet cartridge. If you consult your favourite hi-fi store you’ll find these attributes aplenty in new turntables, but you should expect to pay at least a three-figure sum for them. Avoid plastic turntables at all cost, and pass over the cheap turntables designed primarily for recording your LPs through USB.

If you can’t afford a new turntable, what are your options? There are many decades’ worth of secondhand audiophile turntables out there and you can find bargains, however beware that you’re not paying over the odds for something where a new equivalent would be a better bet. If you’re really strapped for cash though, hit the want ads and the thrift stores. Or ask your older relatives whether their 1970s hi-fi is still gathering dust in the loft. Often the turntable supplied with decent quality mass-market hi-fi systems in the 1970s was surprisingly well-made, and a bit of legwork can still land you one of these unloved and overlooked units for very little money indeed. The turntable in most of the photos on this page for example is an unremarkable JVC turntable from the 1970s with a 2-pole AC motor and a hefty aluminium platter, picked up for a song a few years ago in a junk shop.

It’s important to remember with analogue audio that the most important link in the chain is the first one. Put a bit of effort into sourcing a turntable, and it will reward you.

68 thoughts on “Record Players Explained For The Streaming Generation

    1. “anticlockwise” and “counterclockwise” are acceptable regional variants of the same word (the author is British, the album price given in pounds was a clue). You’re right on point #2 though

  1. I’ve gotten myself one of those audiofool grade turntables from pro-ject two years ago (mainly for the looks, but also because they are based in my homeland of Austria).

    The anti-skating mechanism is a weight as well on those players.

    I really enjoy fiddling around with vinyl. You (or I at least) tend to listen to whole albums, instead of skipping and shuffling playlists. And even the smaller bands tend to sell vinyl again.

    1. The dynamic range is really good on vinyl. Modern digital recordings can use a much wider range if they choose to. In my experience they typically don’t simply because the consumer doesn’t want it or even understand it.

      1. If the mastering for each format is equal then vinyl has worse dynamic range than CD due to the noise floor being higher on vinyl. CD has a base of 96dB and a dithered range up to 120dB with vinyl getting 70dB on a first play.

        Though it’s all kind of moot since i doubt most actual music produced has more than 40dB of range, maybe 60 for some classical or jazz stuff.

        1. It’s possible to record a frequency range of 5Hz to 35Khz on vinyl. CD4 or Quadraphonic records did that, with the rear channels frequency shifted up above 20Khz. A CD4 playback system used a circuit to filter everything over 20Khz and shift it down to the audible range.

          CD4 records required a special stylus and a very responsive cartridge. They could be played with a regular or elliptical stylus but those would wear out the high frequencies faster. If you had CD4 records and wanted to keep them in good condition you made sure to always use the proper equipment and cleaned both record and stylus before each play.

          Redbook audio on CDs has hard cutoffs at 20Hz and 20Khz. It’s impossible to have any infrasonic or ultrasonic sound from a CD. A cheap system playing LPs won’t reproduce any of those frequencies that may exist on the record, but they’ll still effect the motion of the stylus and thus the audible sound produced.

          Recording engineers had to learn new things in order to get the feel of the sound right for CDs, especially for re-releases of old albums. New bands and songs didn’t have that problem because they didn’t have to compare with a previous LP release. Record it directly to digital, edit for the master production tape and it’s done.

          It took a long time for CD pressing plants to accept CD-Rs for masters. they insisted for years that there was no way a CD-R copy for audio could be error free. If you wanted an audio CD mass produced you had to first get it onto a Digital Linear Tape. Before DLT it had to be on a U-Matic video tape.

          Eventually, some of the companies finally got the idea that snubbing CD-R’s for masters was throwing money away. If the customer didn’t care about the minuscule possibility that a few bits would go missing, then why should they, as long as the customer was willing to pay to have a whole bunch of discs pressed? They’d copy the CD-R to DLT and proceed as usual.

          1. Yes, some people can hear higher than 20 kHz, but only for single tones in a silent studio. When you mix them with mid range frequencies, they disappear. Also, the rest of the audio chain is likely to be bandwidth limited anyway.

  2. The most important reason Vinyl is having such a come-back with “hipsters” is that record companies do a crap job mastering audio CD’s nowadays (google for “Loudness Wars). Mastering engineers only do — are allowed to do — their job of carefully adjusting all the levels of each instrument on the multitrack recording so that you can hear everything as intended. Since the late 1990s, CD’s are simply “as loud as possible”: just “throw everything open” and let the compressor/limiter prevent the signal from clipping. Kids are growing up with music where every drum beat pushes the rest of the music away and they think it’s just the best thing ever.

      1. Wow I thought I was the only one to think that Red Hot Chilli Peppers Californication album sounded terrible I thought my amp or player was busted at the time and just glitched up.

        For loudness TV commercials are the worst offenders.

    1. No, a mastering engineer will most likely never ever see the multitrack, or change the loudness of individual instruments. That’s done in the mixing stage. different dude, different profession.
      I also includes ducking and sidechaining which, as I personally think, have their artistic justifications.

      Mastering is more like a check of the mix + checking for artistic and qualitative consistency over a complete Album for example. It’s not uncommon that some engineers just listen to the album and go “that’s nice right where it is. not gonna touch a dial. thanks for the money.”
      But if they really do intervene it’s MUCH more than just running stuff through a dynamic processor to keep it from clipping.

      Not wanting to be Mr Smartypants, i think you are right to be offended by the “loudness war”, however in my opinion it’s a little to generalizing.

  3. I thought audiophiles were silly myself until I got into audio production and started listening to direct masters of songs on high quality studio monitor speakers. You would be blown away by everything you miss from CD or broadcast quality audio. Some songs, though exactly note-per-note the same sound like entirely different songs altogether because the amount of detail that gets lost in compression.

    Vinyl is as much about the experience as anything else. It brings back a lot of memories. From the smell, to the fact you’re probably going to be listening to the whole album as intended through a set of cans.

    Even though I am from more of the cassette era, my dad had a vast vinyl collection I wish was still around now :(

    1. Yeah, while a lot of audiophile lore is just another way to justify having spent more money on something for bragging rights, much of it really is true. I ended up getting a pair of Sennheiser HD 650 heaphones and a decent mobile DAC/Amp to use with my phone and PC. Since then, music has found its way back into my life in a big way. I had been permanently attached to a CD or MP3 player all through high school (two technologies that showed up while I was going through that hormone-fueled phase where music makes the biggest impact on your life), but somewhere in my 20’s I put down all that stuff and forgot about music, for the most part. Now I’ve rediscovered the joy of good music.

      I’m still not going to be running aroind trying to replace both the audio signal cables with OFC litz-braided pure silver wire AND the AC power cords with heavy-gauge solid-core OFC silver conductors. I really appreciate this article because it does a great job of simplifying the list of requirements for a good record player and cutting through the mythology promoted by the vinyl playing audiophile community.

      I’ve been thinking about getting a good record player so I can listen to my dad’s vinyl collection. I get my good taste in music from him, so a lot of those records are albums to which I would love to listen. Finding something that would compliment my headphones (or the Noble 3 IEMs I picked up) in an affordable way would allow me to do that.

  4. A programmable record player was an important plot device in one of my favorite episodes of Columbo. The killer rigs it to play a song, set off some ‘sqibs’ (tiny firecrackers), and then the arm knocked over a highlighter that upsets a perfectly-balanced gigantic dictionary.

  5. I lost my record collection and old (pretty high quality) stereo-tower in a divorce, and it got little to no use by my ex.

    To my total suprise, my daughter and her boyfriend both wanted it, and my ex let them have it.

    They still play the same records I did 30 years ago, on the same equipment, and they also buy their own music on vinyl.

  6. TL;DR (I will read it later) but from skimming one thing bothered me, “Often the best available without spending serious money at an audiophile store is a USB device with the cheapest possible manufacture, from which the playback will be mediocre at best.” Wouldn’t the best available be used equipment, I mean 30 years isn’t that long ago, there must be used equipment that is both useable and reasonably priced, and with hackers, you could revive a piece of equipment that is cheap and just slightly busted.

  7. I was feeling nostalgic and more than a little irritated at my latest misadventures in HDMI handshake failures and picked up a Perfectly Fine BIC. Fiddling with something purely mechanical was just a blast and I still enjoy the thing. Got the tracking weight just so, the anti-skate…. anti-skating. However, I declined to figure out what the cartridge protractor is for. That feels like bullshit.

    To date there has not been ONE SINGLE HDMI handshake failure between the phono and the 80’s NAD amp nor have I been required to update any drivers, accept any license agreements, or type in any god damned passwords!

    PS. A battered copy of The Sound Of Music was sacrificed to test the absurd myth that you can “restore old records” by “pulling out the vinyl dust embedded deep in the pits” by smearing wood glue all over it, letting it dry, and peeling it off. It did not, in fact, do shit. Kinda cool looking though.

    1. Have you tried playing “wet”? Mix 500ml of distilled water with 500ml of methanol (or ethanol, but I can think of better uses for ethanol), add 1-2 drops of dishwashing detergent (or ethylene glycol, photographic wetting agent), immerse a clean cloth, then wring it out until it *just* stops dripping, and drag that across the surface of the vinyl, so that it’s wet but not dripping, play while wet, and dry it afterwards. Play a track dry first, note any pops or crackles, then play it wet and hear the difference. Also reduces wear from friction.

      1. Then rinse in deionized water, dry in sterile conditions. Repeat when played again. Play only in conditions of 100% humidity because drying is like throwing sand on the record!

        Or, Just clean the disc with said formula and dry as said. Then you will have the best clean surface, just keep it that way. Having a Watts record brush I took a battered copy of West Side Story original soundtrack thru this and it’s amazing what comes thru in the end.

    2. The cartridge protractor is (if it of good quality and accurate) a valuable tool for alignment. The angle of your cartridge relative to the tone-arm can make or break the vinyl-listening experience. There are plenty of good explanatory articles out there already, but the TL;DR is that how you align the cartridge effects how the stylus is aligned in the groove. You might not notice anything with a true conical stylus, but with any of the elliptical styli having it anywhere other than true means that you’re getting more of one side of the groove than the other… you’ll get smearing and phase-alignment issues on stereo playback and imbalanced levels on mono playback.

      Generally, the mechanics of a decent turntable are such that you can eyeball your cartridge alignment and get a generally-listenable output. But, doing an A/B of the before and after of a cartridge alignment can be an eye-opening experience. That level of effort might not be desirable for everyone, but those that do undertake it correctly usually end up with a noticeably superior sound, especially when the rest of their stereo system is properly balanced for the listening environment.

  8. get a scrapped “in-dash” car record player and hack in a standard needle so it can play regular 45 records (is non-standard unit, otherwise your car-cartridge and car-records are probably dead anyway) then, using suspenders, foam, and ducttape mount unit inside a box to suspend it by, in-dash players are already 12 volt so use 12v-batt and away you go! playing PORTABLE records, just dont expect to play skip-rope while carrying and playing XD

  9. Who remember automatic record changers? Stack a dozen records on the spindle and play music for hours. Multi disc sets used to be made for them, with the tracks and sides ordered for stack changers.

    In the playback accuracy field there were linear tracking players of two main types. The higher end ones tracked perfectly straight and smoothly from edge to center. The less expensive ones had the tonearm move in a short arc until a sensor was tripped, then the arm mount would be moved ahead to wait for the arm to pivot again.

  10. One problem in old turntables is very sticky lube. It’s in some very deft little things hidden inside of the semi automatic turntables.

    Oh! They left out the thing about semi-automatics and full auto. They are all legal, although an audiophile won’t carry full auto. A manual will have to be set on the start groove and …..tic…..tic…..tic will have to be lifted at the end. A semi will lift it self at the end and may start hands off too. This is a subset of the full auto which also has a long spindle to hold 6-8 records above a notch on the spindle with an over arm to stabilize the stack. A little bit pushes one record off of the notch to plop on the turntable before the arm moves to 12,10,or 7 start position and then drop. These were the most articulate ‘robotic’ automation in most homes at the time. Music for more than an hour unattended. If it failed, ouch! So most people use them to play just one record at a time, good ones had a short spindle to make it easy.

    I still have very clean stuff starting with Beatles VI, what I tend to call THE DECADE 64-74. But! First I don’t like to get it out, second it’s not even as convenient as cassettes which I used heavily for years. I need to put some vinyl on my computer so I can listen with my phone and play at socials, in 24/96 though! No m-pee. Good turntable and preamp, line in PC and Audacity and I can have vinyl that fits in my pocket. Without ticks, pops, swish, bumps, wow, and worst of all rumble. Dancing and turntables never mixed well except at a disco where they were on heavy things.

    Then there is the problem with powerful bass. No not the sub giving feedback to the turntable, but little bass in the bottom octave on most records that had pop appeal and would be played on those cheapest of cartridges ceramic or worst of all crystal. The needle would skip and prompt a sales return, so they compromised. The bass we bump to today wasn’t on many of those records from The Decade. Also RIAA doesn’t just roll-off (not cut) the bass, but boosts the treble to give a better noise factor than if not done. This is all reversed upon playback of course. About a decade before The Decade every label had it’s own EQ curve, then the RIAA set a standard, RCA’s new orthophonic.

    This couldn’t be done today though. The boost is called pre emphasis and is like passive Dolby noise reduction. It needs the spectral footprint of pink noise which is natural sound. Sometime in the 80’s sound mixing and mastering went into the hearing damaging meltdown of white noise which defines equal amplitude across the band rather than bass being two orders of magnitude stronger than the top end. The super treble would saturate if boosted before cutting the groove. This issue of Pink vs. White noise is at the heart of the loudness wars.

  11. I actually just today started planning out a homebuilt phono made primarily from extra 3d printer parts (Aluminum T-extrusion, radial bearings, GT2, etc.) I’m not sure about the platter or the tonearm yet (probably ebay for the later), but I’m hoping to run the whole thing off an Uno and a MAX97 amp. The plan is to keep costs down to just the amp, DCBM, tonearm, and platter keeping the whole thing under $50 (but I’m sure we all know how those plans go).

  12. This is hackaday, I was expecting someone to come up with a way to play back vinyl record with nothing more than a green laser and an ardino. And then maybe printing copies with a 3D printer. What’s this site coming to?

    1. That should be doable. Looking at the patent filing for the “Laserphone” (#3,992,593 from 1976) a lot of the heavy lifting could be handled by an UNO.(It’s amazing, sometimes, to look at 40 year old patents like this, and see how complex and expensive they are and think: “Yeah. I can probably make that with modified code off the internet and $50 in parts from AliExpress.”)

      The patent design relies on a Helium Neon laser, which runs in the red wavelength, so if I wanted to stick with that general design I’d probably try to salvage a red diode from a DVD-rom. To avoid having to build a big enclosure you could set it up so the album is read from the underside (square spindle, print a frame (Something really stiff, nylon or a nylon substitute, nGen or Armadillo maybe?) that holds the record from the outside edge w/ supports running to the spindle across the top)…

      OK. Now you’ve got me thinking about it. I can’t promise it will be soon (It’s Technology Student Association season after all), but I’ll try to work this out, and maybe when I do hackaday will write an article about it. =)

  13. There’s nothing “unpredictable” at all about vinyl resurgence – it’s the exact same thing as retrogaming and the rest of the nostalgia-fuelled fads resurrected by the 80’s generation ageing to reach their first nostalgic peak. Watch for equally retarded “only iPods are truly worth listening to!” and “CRT tones are so much more natural than LCD!” bullshit incoming in another decade or two…*

    * I have nothing against those who simply enjoy using retro tech and admit that – only those who try to insist they do it because it’s “superior”

    1. You nailed it. :-) Somewhat similar, there are those who think CRT projectors are inherently superior to DLP or LCD projectors and they consider aligning all three red green and blue images together a joy. I can tell you form experience it is a very tedious process but I’ve learned that humans can be conditioned to enjoy any process including ones that are painful. That said, I have no sense of nostalgia about CRT projectors. They were nice and quiet though. :-)

  14. Pre;–WW II record players used replaceable needles, usually steel, which should be changed quite often. Cactus needles(!) were also used. Tracking force was maybe an ounce or so, maybe more.
    (I’ve seen multimeter test prods with chucks to hold steel needles.)

    The advent of LPs, postwar, meant that the pickup needed to be more sophisticated, and its point was called a stylus. This article’s use of “needle” follows decades–old custom.

    Beware of worn styli; they can damage the record. Serious audio equipment stores had microscopes for examining styli. Pretty sure that flat spots develop.
    Stylus tips are made of diamond.


    A contactless player was developed maybe 15 years ago, very roughly. It had iirc five diode lasers, some to track the groove, and some to sense the audio.


    The fanciest record changer picked up the played stack and turned it over, then positioned it for playing. It was known to malfunction (at least, so the story goes) by ejecting records across the room.

    I s.t.r. a juke box that played 45s upside down as well as normally, to simplify handling.


    In the early 20th century, acoustic phonographs had turntables driven by big mainsprings, wound by hand, and adjustable speed (not all early disc records were meant to be played at 78 rpm, fairly sure).

    Speed was set by “flyball” centrifugal governors, like those on stationary steam engines, but a lot smaller.
    Flyballs moved a brake disc along the shaft to limit speed.


    Pre–WW II records were made (fairly sure) of shellac, which was brittle; they tended to break when dropped.
    The advent of vinyl was quite happy!

    Many, perhaps all of the earliest disc records were single–sided, with a raised pattern on the bottom to prevent slipping. I s.t.r. felt–surfaced turntables.


    What with constant groove pitch (spacing), 78s were limited to maybe 3½ minutes per side. Most classical music had to be excerpted and arrranged. Advent of LPs after the war was a joy for some!
    Variable pitch was developed, with early playback from the tape by an extra head.

    For longer–lasting music, sets of records were sold in albums with stiff covers, stout spines, and heavy kraft paper sleeves for each record. The sleeves had holes so you could read the labels.
    Loosely speaking, an entire record could correspond to part of one side (“track”?) of an LP.
    This is the origin of “album”, referring often to one LP.


    The article was rather weird regarding how it described turntable drive motors. Not sure what’s significant about two–pole motors (high speed?). Shaded poles are used in low–cost induction motors, such as for fans, so their speed can’t be just right and unchanging.

    Some better turntables used hysteresis synchronous motors, so their speed was set by the power line/mains frequency.

    I just recalled a turntable motor called the “Green Flyer”,
    painted green. It had a narrow–range speed adjustment, like those on spring–driven turntables. Free running, it was slightly too fast, but the extra load on the (induction) motor was not excessive.


    There were 16″ diameter turntables, used for radio broadcast distribution; called transcription recordings, they played at 33⅓ rpm, quite likely the same groove size as 78s. Recordings were not time–critical.
    Around 1975, the Manhattan School of Music had a modern tone arm made to play those, but with an LP stylus and cartridge. Idea was to reduce tracking error.


    There was a direct–drive turntable for 78’s that used a multipole (~46?) 60 Hz synchronous motor; iirc it ran at 78.26 rpm.


    Pretty much off-topic, but a few decades ago there was a line of greeting cards that included a long strip that looked like a zip (cable) tie. You’d insert the beginning end into a slit in the (fairly stiff) card, pull steadily, and a quite intelligible voice said “Happy Birthday!” or “Merry Christmas!”


    Then, abused records could have groove damage that made the stylus jump back to the previous turn of the groove, causing repeats — origin (afaik!) of the term “broken record”.


    The first audio recording was made with a “horn”, )diaphragm and stylus on a smoked cylinder, before playback became possible. Within the past year or two, the wiggles were (probably transferred) and converted (one assumes) to a digital audio file. Try Ganot’s Physics, roughly 1870?, Google Books. Was called the Phonautograph, iirc.

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